“…Synthesis of ent-codeinone and ent-codeine via nitrone cycloaddition. i) E. coli JM109 (pDTG601A), 5 g L À1 ; ii) potassium azodicarboxylate (PAD), HOAc, MeOH, 84%; iii) TBSCl, imidazole, DMF, 54%; iv) DIAD, (n-Bu) 3 P, THF, phenol 9, 79.5%; v) PdA C H T U N G T R E N N U N G (dba) 2 , K 2 CO 3 , (t-Bu) 3 P, toluene, reflux, 64%; vi) 50% aqueous TFA, toluene, 50 8C, 92%; vii) NHMeOH·HCl, Hünigs base, toluene, reflux, 38%; viii) Meerwein salt, CH 2 Cl 2 , then LiAlH 4 , THF, 76% over 2 steps; ix) Dess-Martin periodinane, CH 2 Cl 2 , 75%; x) NH 2 Me·HCl, NEt 3 ,TiA C H T U N G T R E N N U N G (i-PrO) 4 , MeOH, then NaBH 4 ; xi) BOC anhydride, EtOH, 66% over 3 steps; xii) TBAF, THF; xiii. Dess-Martin Periodinane, CH 2 Cl 2 , 51% over 2 steps.…”